The present invention relates generally to chewing gum. More specifically, the present invention relates to methods of improving the shelf-life of chewing gum and the packaging of same.
During storage, chewing gum has a tendency to lose or gain moisture from the surrounding atmosphere depending on the surrounding temperature, relative humidity, and packaging, and also depending on the shape and formulation of the chewing gum. Sugar-containing chewing gums, for instance, typically contain corn syrup and a small amount of humectant such as aqueous sorbitol or glycerin. Such sugar-containing chewing gums have a tendency to dry out and become brittle when stored under relatively dry conditions of 50% relative humidity and lower. The tendency of sugar gums to dry out and become brittle is particularly apparent at higher ambient temperatures.
Sugarless chewing gums are typically designed to contain lower amounts of moisture than sugar-containing gums. In sugarless gums which are sweetened with aspartame or other moisture-susceptible artificial sweeteners, it is important to maintain a low moisture content in order to prevent loss of sweetness and flavor qualities. However, due to their low initial moisture content and higher level of hygroscopic ingredients, these sugarless gums tend to gain moisture above 40% relative humidity, causing wetness of the chewing gum and degradation of the aspartame or other moisture-susceptible ingredients.
Various technologies have been developed for the purpose of protecting chewing gum from moisture loss, moisture gain and other adverse changes which result from storage. For example, packaging techniques have been developed which provide sealed, high quality protective packaging for individual chewing gum sticks. One such technique is disclosed in U.S. Pat. No. 5,048,260 to Raymond et al.
For example, it is known to generally package stick chewing gum in a wrapper that comprises a composite material having a tissue or paper substrate that defines an inner surface that contacts the chewing gum and a metal foil outer surface. The foil surface provides moisture and vapor barrier properties to the wrapper.
Typically, the composite wrapper does not provide sufficient barrier properties for long term storage of chewing gum. It is therefore known to house a group of individually wrapped gum sticks in, for example, a package more commonly referred to in the industry as a counterband. The counterband is usually also a composite material, such as, an inner layer of aluminum foil with a paper and/or polypropylene outer surface. The counterband seals the individually wrapped sticks of chewing gum until opened by the customer.
Although the composite wrapper and counterband provide sufficient barrier properties allowing long term storage of chewing gum, they raise a number of issues. One issue is cost. The use of a composite wrapper as opposed to only a paper or tissue wrapper substantially increases the packaging costs. Indeed, for at least certain chewing gum products, the packaging costs can comprise a substantial portion of the product costs. However, for a typical chewing gum composition if a composite wrapper is not used, shelf-life may be substantially compromised. This is especially true once the counterband has been opened. For chewing gums that use only paper on the single piece, the paper offers virtually no protection from the environment.
A further issue is with respect to environmental concerns. Foil wrappers and counterbands do not biodegrade, or are not easily recyclable, and therefore, are not "environmentally friendly." Although environmental concerns have been a concern for a number of years, recently, much greater attention has been focussed on biodegradability and the recycling of materials.
There is a need or desire for improved packaging that still allows for sufficient shelf-life of chewing gum products especially chewing gum sticks.